1. Field of the Invention
This invention relates to the field of home accessories. More specifically, the invention comprises a doorbell which displays a status message informing a visitor whether the house is receiving guests.
2. Description of the Related Art
Electrical doorbells have been in common use for many decades. FIG. 1 shows a typical prior art device. Chime unit 14 is mounted on a wall in the interior of a house, typically in a hallway. 110VAC is provided via line power 30. Two wires run to activation button 12, which is mounted next to the front door. The two wires comprise activation circuit 16. When button 12 is pressed, a circuit is made and the tone generating chimes within chime unit 14 are activated.
The chime unit is typically loud enough to alert everyone in the home. Its activation can cause unwanted disturbance, however, in the case of sleeping infants. Since it often requires quite some time to induce sleep in an infant, once disturbed, the infant may remain awake for some time. Thus, an unwanted activation of chime unit 14 can be a big problem. It would therefore be advantageous to provide some indication as to whether visitors are welcome.
Those skilled in the art will know that the two wires comprising activation circuit 16 customarily carry a 10-16VAC potential. This potential is typically provided by a step-down transformer within chime unit 14. In a sense, the activation circuit is always “made”, in that a light within the button is customarily powered by the activation circuit (thereby illuminating the button). However, the light source is a high resistance connection that allows very little current flow within the activation circuit. When the door bell button is pressed, this “makes” a low resistance connection which allows substantial current flow and the activation of the chime unit itself. The existence of the low-current 10-16VAC potential on the activation circuit is significant, since it can be used to power devices located proximate the door bell button.